Short-circuiting device for motors



, Aug. 12 1924.

C. P. EISENHAUER SHORT CIRCUITING DEVICE FOR MOTORS 2 Sheets-Sheet l Filed Aug. 25 1921 Aug. 12 1-924. 1,504,438

C. P. EISENHAUER SHORT CIRCUITING DEVICE FOR MOTORS Filed Aug. 25 1921 2 Sheets-Sheet 2 Patented .Aug. 12, 1924.

UNITED STATES PATENT other.

CHARLES P. EISENHAUER, or DAYTON, OHIO, ASSIGNOR TO THE nuao & MANUFACTURING COMPA Y, or DAYTON, oHIo, A CORBORA'IION or omto.

Application filed August 25, 1921.

To all .whom it may concern:

Be it known that I, CHARLES P. EISEN- BAUER, a citizen of the United States, residing at Dayton, in thecounty of Montgomery and State of Ohio, have invented certain new and useful Improvements in Short-Circuiting Devices for Motors, of which the following is a specification.

My invention relates to improvements in single phase repulsion induction motors, and

articularly to the means for short-circuitmg the armature of the motor after the motor has started and reached. maximum speed.

The object of my invention is to provide a short-circuiting device which will be simple in its construction and effective in its operation; also one that is compact in character in that it occupies but small space compared with other devices of this character; and also one in which friction is reduced to the minimum.

Referring to the drawings Fig. 1 is a longitudinal sectional view of a motor of the type referred to embodying my improved short-circuiting device.

Fig. 2 is an enlarged longitudinal section of the short-circuiting device and associated parts.

Fi 3 is an end View of the short circuiting evice as viewed from the left of Fi 1. Fig. 4 is a view of the opposite end of the same.

Fig. 5 is an end elevation of a modified form of a short circuiting device.

Fig. 6 is a longitudinal section of the same showing the commutator associated therewith.

Fig. 7 is an end elevation'of a further modification of the device.

Fig. 8 is a longitudinal section of this latter modification showing the commutator associated therewith.

Referring to the drawings, 1 represents the supporting casing, 2 the fields, 3 the armature, 4 the armature shaft, 5 the commutator cylinder, 6 the commutator bars, and b one of the brushes of an electric motor of the type referred to; the bars in this case being arranged so that their brush contacting faces are disposed parallel with the axis of the shaft.

Referring first to the construction shown in Figs. 1 to 4, inclusive, showing my preferred form of .short circuiting device, 7 represents a metallic disk having a hub 8 SHORT-CIRCUITING DEVI-CE son Morons.

Serial No. 495,393.

fast to the shaft 4. This disk is provided with a series of four pairs of slotted openings, 9' and 1O, arranged ninety degrees apart, with the slots of each pair disposed radially in line with the other; the outer slots 9 of each pair being preferably extended to the'periphery. Slidably connected to one end of this disk by headed studs 11 which extend through the slotted openings, are four metallic segments 19. each carrying a series of copper contacts 13, each of which may be integrally formed from a single piece of metal, riveted to its segment and slotted as shown in Fig. 4, to divide the same in separate .contacts. These contact carrying segments are normally drawn toward the axis of the shaft 4 by springs 14connected with the outermost studs 11 at one end and with lugs on the hub 8 at the other end, but move outwardly bycentrifugal force against the tension of the springs when the shaft is in motion and'make contact with the bars 6 when the desired maximum speed is reached to thereby short-circuit the armature; the disk 7, on that end thereof adjacent the segments 12 being preferably provided with spacingribs 15, two for each segment and extending in the direction of movement of the segments, to reduce friction, these ribs being formed by punching in the metal of the disk.

In order that the contacts 13 may make a goods electrical connection with the bars 6, the outer end of each contact is bent upon the arc of a circle as indicated at 13 and the adjacent end of each commutator bar is projected beyond the cylinder and formed with an inclined face at its lower corner as shown at 6?; the metal of the contacts 13 being sufficiently thin to beof a resilient character.

In-Figs. 7 and 8 is shown a modification in which but three contact carrying segments 12' are employed (shown in dottedlines) in Fi 7. These segments are connected with a isk 7 by the headed studs 11 operating in slotted openings similar in all respects to the preferred construction described with the exception that the disk 7 :has but three pairs of radially arranged slotted'openings 9 and 10'. In this construction, the springs 14' connect the outer studs 11' of one segment with the corresponding studs of'the adjacent segments.

In Figs. 5 and 6 there is shown a further modification in which there is fast to the I armature shafi' t'a disk 16, arranged adjacent to the/outer end of the commut tor and having itI outer portion flared or inclined toward the ends of the commutator bars as ,5 indicated at 16' so that the inner surface of this inclined portion will form a guide for a garter spring-17 arranged between the disk arid the commutator so that when the [garter spring is expanded by the centrifugal loaaction' ofa series of weights 18 arranged within the spring, it will be forced into contacttwith the ends 'of the commutator bars.

Tj 'l-iaving thus described my invention, I claim?- 1. In a motor of the character described, the combination with an arn'iature shaft and ,a commutator having a series of bars, of -a disk mounted to rotate with'said shaft,- a plurality of contacts slidably connected with said disk, and springs normally tending to hold the same toward the axis of the shaft, said contacts being located in line with the ends of said bars so as to contact with said bars when impelled radially outwardly bycentrifugal force. a

2. In a motor of the character described, the combination with an armature shaft and a. commutator'cylinder having a series of bars arranged thereon with one end of each of said bars projected beyond said cylinder, of a disk mounted to rotate on said shaft, a series of contacts slidably connected with said disk and arranged to move outwardly b centrifugal force to make contact with tli e projecting ends of said bars, and springs for tending to hold said movable contacts toward the axis of said disk.

mutator, a short-circuiting means, and a series of segmental weights supporting said short-circuiting means and adapted through centrifugal action to cause such means to engage the commutator.

4. A short-circuit device for electric motors, including in combination with a commutator, a short-circuiting means, and a series of independently acting segmental weights supporting said short-circuiting means and adapted through centrifugal ac tion to cause such means to engage the commutator.

5. In a short circuiting device, the combination with the commutator bars, of a disk mounted at the ends of said bars to rotate therewith, a series of se ments slidably connected with said disk an movable outwardly by centrifugal force, springs'tending to pull said segmenttoward the axis of said disk, and a-series of contacts carried by each segment, the said bars being arran ed in the path of the outward movement 0 said contacts.

' In testimony whereof, I have hereunto set my hand this 2d day of July 1921.

CHARLES P. EISENHAUER. Witnesses:

ALBERT H. ToRA, ROBERT B. Moms. 

